Both landscape and local factors influence plant and hexapod communities of industrial water-abstraction sites.

At the landscape level, intensification of agriculture, fragmentation, and destruction of natural habitats are major causes of biodiversity loss that can be mitigated at small spatial scales. However, the complex relationships between human activities, landscapes, and biodiversity are poorly known. Yet, this knowledge could help private stakeholders managing seminatural areas to play a positive role in biodiversity conservation.We investigated how water-abstraction sites could sustain species diversity in vascular-plant communities and two taxonomic groups of insect communities in a fragmented agricultural landscape.Landscape-scale variables (connectivity indices and surrounding levels of herbicide use), as well as site-specific variables (soil type for vascular plants, floral availability for , and low herbaceous cover for ), were correlated to structural and functional metrics of species community diversity for these taxonomic groups, measured on 35 industrial sites in the Ile-de-France region in 2018-2019. and consisted essentially of species with a high degree of dispersal and low specialization, able to reach the habitat patches of the fragmented landscape of the study area. Sandy soil harbored more diverse vascular-plant communities. Plant diversity was correlated to a greater abundance of and a lower richness of .Increasing landscape connectivity was related to higher abundance of plants and , and a higher evenness index for communities. Higher levels of herbicide use were related to a decrease in the biodiversity of plants and abundance. High levels of herbicide favored high-dispersal generalist plants, while high levels of connectivity favored low-dispersal plants. Specialist species were associated with low herbaceous cover and connectivity.Water-abstraction sites are valuable seminatural habitats for biodiversity. Changing intensive agricultural practices in surrounding areas would better contribute to conserving and restoring biodiversity on these sites.